#include <iostream>
using std::cout;
using std::endl;

void xout(){
    printf("xout\n");
}

namespace wd
{
//命名空间中可以放变量、函数、类、命名空间，统称为实体
//编程规范：定义实体不用缩进，实体内正常缩进
int num = 100;

void print(){
    cout << "wd::print()" << endl;
}

namespace cpp
{
int num = 200;

void print(){
    cout << "wd::cpp::print()" << endl;
}
}//end of namespace cpp
}//end of namespace wd


using namespace wd;
/* using namespace wd::cpp; */
void test0(){
    cout << num << endl;
    cout << cpp::num << endl;
    wd::print();
    wd::cpp::print();
}

int main(void){
    test0();
    return 0;
}
